Download Protein Requirements for Good Nutrition

Protein Requirements for Good Nutrition
Drs. Foster & Smith Educational Staff
Proteins are the building blocks in animal nutrition. They are one of the most important nutrients in the diet and are currently
one of the most widely debated. For around twenty thousand years as dogs, and for several million years before that as
wolves, the only problem canines had with protein was getting enough of it. Dogs ate a primarily meat diet and with that
consumed a high percentage of their diet as protein. With their meat diet they also got a fair portion of fat and a little fiber
and carbohydrate thrown in, but primarily they ate meat. Cats were pretty much the same only they were even stricter
carnivores and did not eat any carbohydrates.
The discussion about protein started around World War II when commercial dog foods became more available and they
began to replace the traditional meat and meat by-product diet. At first, the cheaper forms of leftover meat were put into the
food with little regard for flavor or fashion. But with the interest in health as related to diet, a whole new generation of dog
foods have entered the market. These quality foods challenge the earlier foods by promoting a product that is better than ever
for our pets. At the center of debate for the newer products is protein, its source, digestibility, and quantity. Hopefully this
article will answer some of the questions concerning protein in your pet's diet.
Amino acids
Why do dogs and cats need protein? Proteins are necessary for all aspects of growth and development and are very important
in structural make up and the immune system. In addition, they are burned as calories and can be converted to and stored as
fat.
In reality, our pets do not need the protein but they need the building blocks that make up the protein, amino acids. There are
22 amino acids that animals need. Animals can synthesize 12 of them. The remaining ones must be consumed. The ones that
the animals cannot synthesize are called essential amino acids. They are arginine, histidine, isoleucine, leucine, lysine,
methionine, phenylalanine, threonine, tryptophan, valine, and in cats, taurine. Dogs can synthesize taurine, and therefore, it is
not supplemented in their food. This is why there is the old adage that dogs can eat cat food but cats cannot eat dog food. A
deficiency in any of the amino acids can cause health-related problems.
Protein quality
Every protein source contains different levels of amino acids and each protein is different in its ability to be broken down into
amino acids. So not all proteins are created equal. Some are better for pets than others. The ability of a protein to be used by
the body and its amount of usable amino acids is summarized as protein quality (biological value). Egg has the highest
biological value and sets the standard for which other proteins are judged. Egg has a biological value of 100. Fish meal and
milk are close behind with a value of 92. Beef is around 78 and soybean meal is 67. "Meat and bone meal" and wheat are
around 50 and corn is 45. Things like hair and feathers would be very high in protein but would be down at the bottom of the
list for biological value. The actual composition of individual proteins as well as the utilization of amino acids is very
detailed and beyond the scope of this article, but in summary, we see that all proteins are not created equal.
Protein requirements
Protein requirements vary from species to species and can vary greatly during the rapid growth stages and for elderly animals
with compromised kidneys. I will explain some of the special circumstances that require altered levels of protein but as a rule
the following levels apply.
Species and
Growth Stage
Recommended
Protein %
Recommended
Fat %
Puppy
28%
17%
Adult dog
18%
9-15%
Performance dog
25%
20%
Racing sled dog
35%
50%
Protein Requirements for Good Nutrition - Page 1 of 2
Unauthorized use of any images, thumbnails, illustrations, descriptions, article content, or registered trademarks of Foster & Smith, Inc. is strictly
prohibited under copyright law. Site content, including photography, descriptions, pricing, promotions, and availability are subject to change without
notice. These restrictions are necessary in order to protect not only our copyrighted intellectual property, but also the health of pets, since articles or
images that are altered or edited after download could result in misinformation that may harm companion animals, aquatic life, or native species.
Lactating dog
28%
17%
Pregnant and lactating dogs may need to be fed puppy chow to give them the necessary protein. Sick, weak, and debilitated
animals also need extra protein. Animals with kidney disease may need to be on a protein-restricted, but high biological value
diet to lessen the effects of the kidney disease.
Can I feed too much protein?
The answer to this is yes and no. In theory, if a healthy animal eats too much protein, some gets excreted in the urine and the
rest just gets used as calories or is converted to fat and does not cause any harm. Protein is the most expensive ingredient in
the food and why pay for more than you need. Most pet food companies strike a happy medium and meet the minimum
recommended requirements and add a little extra to be safe.
Interpreting the pet food label
This is where the hard part comes in. You now have two choices. The first is to buy a reputable quality brand of dog food for
the activity level of your dog and hope that its needs are being met. This is what most owners do and the average dog does
just fine. But if you have a dog with special protein needs or want to search out the best possible food for the money then you
must dive into the label and try to interpret it.
If you have been reading so far, you know that not all proteins are created equal. The listing of protein level on the bag or can
is not a listing of the percent of digestible protein, just a listing of percent protein. So we need to know how to interpret the
pet food label. We know that in quality foods digestibility is between 70 and 80%. In lesser quality foods the digestibility
could drop to 60% or less. The way to determine the digestibility is not very scientific but is the best we have until the pet
food industry begins to list digestibility. By reading the ingredients and noting the order that they appear we can roughly
determine the digestibility. The ingredients are listed in order of weight. If the first ingredient is chicken or lamb or other
meat, we can assume it is a good quality protein source. Meat meals such as lamb meal also provide quality protein. "Meat
and bone meal" is an ingredient that is less desirable. If grains are listed, they are not as digestible sources of protein and
contribute heavily toward the carbohydrate load. Some companies will list a meat source and then three different forms of
corn, hiding the fact that the main ingredient is corn but just divided into three different products.
Protein Requirements for Good Nutrition - Page 2 of 2
Unauthorized use of any images, thumbnails, illustrations, descriptions, article content, or registered trademarks of Foster & Smith, Inc. is strictly
prohibited under copyright law. Site content, including photography, descriptions, pricing, promotions, and availability are subject to change without
notice. These restrictions are necessary in order to protect not only our copyrighted intellectual property, but also the health of pets, since articles or
images that are altered or edited after download could result in misinformation that may harm companion animals, aquatic life, or native species.